To reveal the cardiac immune landscape of mouse heart in steady state, we performed single-cell RNA-sequencing (scRNA-seq) with heart tissue from wide type mice and immune subsets were analyzed to reveal cardiac immune features. Overall design: We performed single-cell RNA-sequencing (scRNA-seq) with heart tissue from wide type C57BL/6 mice (n=6). We constructed one library with CD45+DAPI- cells purified from pooled enzymatically digested hearts by FACS.